Add the opt-in Metadata trait, replacing SWIFTPM_BLUETOOTH_METADATA

Package.swift

@@ -4,7 +4,6 @@ import CompilerPluginSupport
 
 // get environment variables
 let dynamicLibrary = Context.environment["SWIFT_BUILD_DYNAMIC_LIBRARY"] == "1"
-let buildMetadata = Context.environment["SWIFTPM_BLUETOOTH_METADATA"] != "0"
 let generateCode = Context.environment["SWIFTPM_ENABLE_PLUGINS"] != "0"
 let enableMacros = Context.environment["SWIFTPM_ENABLE_MACROS"] != "0"
 let buildDocs = Context.environment["BUILDING_FOR_DOCUMENTATION_GENERATION"] == "1"
@@ -53,6 +52,23 @@ var package = Package(
             targets: ["BluetoothSDP"]
         )
     ],
+    traits: [
+        .trait(
+            name: "Metadata",
+            description: """
+                Bluetooth SIG assigned-numbers metadata: the `name` \
+                properties of `CompanyIdentifier`, `BluetoothUUID` and \
+                `UnitIdentifier`.
+
+                Opt-in because it pulls in Foundation and a resource \
+                bundle, which makes the package neither Embedded-clean \
+                nor buildable outside SwiftPM. The numeric definitions \
+                themselves (`CompanyIdentifier.apple` and friends) are \
+                generated at build time and remain available without it.
+                """
+        ),
+        .default(enabledTraits: [])
+    ],
     targets: [
         .target(
             name: "Bluetooth"
@@ -100,7 +116,10 @@ var package = Package(
                 "Bluetooth",
                 .target(
                     name: "BluetoothMetadata",
-                    condition: .when(platforms: [.macOS, .linux, .macCatalyst, .windows])
+                    condition: .when(
+                        platforms: [.macOS, .linux, .macCatalyst, .windows],
+                        traits: ["Metadata"]
+                    )
                 ),
                 .target(
                     name: "BluetoothGAP",
@@ -124,11 +143,16 @@ var package = Package(
 )
 
 // Optional dependencies
-if buildMetadata {
-    package.targets[0].dependencies += [
-        "BluetoothMetadata"
-    ]
-}
+//
+// The metadata tables are reached only through `canImport`-guarded code
+// in `Sources/Bluetooth`, so conditioning the dependency on the trait is
+// enough to compile them out.
+package.targets[0].dependencies += [
+    .target(
+        name: "BluetoothMetadata",
+        condition: .when(traits: ["Metadata"])
+    )
+]
 
 if embeddedFoundation {
     package.dependencies += [

Sources/Bluetooth/BluetoothUUID.swift

@@ -56,7 +56,7 @@ extension BluetoothUUID: Equatable {
 extension BluetoothUUID: CustomStringConvertible {
 
     public var description: String {
-        #if canImport(Foundation) && canImport(BluetoothMetadata) && !os(WASI) && !hasFeature(Embedded)
+        #if Metadata && canImport(Foundation) && !os(WASI) && !hasFeature(Embedded)
         if let name = self.metadata?.name {
             return "\(rawValue) (\(name))"
         } else {
@@ -73,7 +73,7 @@ extension BluetoothUUID: CustomStringConvertible {
 extension BluetoothUUID: LosslessStringConvertible {
 
     public init?(_ string: String) {
-        #if canImport(Foundation) && canImport(BluetoothMetadata) && !os(WASI) && !hasFeature(Embedded)
+        #if Metadata && canImport(Foundation) && !os(WASI) && !hasFeature(Embedded)
         var rawValue = string
         var name: String?
         // Find UUID name

Sources/Bluetooth/BluetoothUUIDMetadata.swift

@@ -5,7 +5,7 @@
 //  Created by Alsey Coleman Miller on 1/12/25.
 //
 
-#if canImport(Foundation) && canImport(BluetoothMetadata) && !os(WASI) && !hasFeature(Embedded)
+#if Metadata && canImport(Foundation) && !os(WASI) && !hasFeature(Embedded)
 #if canImport(FoundationEssentials)
 import FoundationEssentials
 #else

Sources/Bluetooth/CompanyIdentifier.swift

@@ -50,7 +50,7 @@ extension CompanyIdentifier: ExpressibleByIntegerLiteral {
 extension CompanyIdentifier: CustomStringConvertible {
 
     public var description: String {
-        #if canImport(Foundation) && canImport(BluetoothMetadata) && !os(WASI) && !hasFeature(Embedded)
+        #if Metadata && canImport(Foundation) && !os(WASI) && !hasFeature(Embedded)
         return name ?? rawValue.description
         #else
         return rawValue.description

Sources/Bluetooth/CompanyIdentifierMetadata.swift

@@ -5,7 +5,7 @@
 //  Created by Alsey Coleman Miller on 1/12/25.
 //
 
-#if canImport(Foundation) && canImport(BluetoothMetadata) && !os(WASI) && !hasFeature(Embedded)
+#if Metadata && canImport(Foundation) && !os(WASI) && !hasFeature(Embedded)
 #if canImport(FoundationEssentials)
 import FoundationEssentials
 #else

Sources/Bluetooth/UnitIdentifier.swift

@@ -30,7 +30,7 @@ extension UnitIdentifier: ExpressibleByIntegerLiteral {
 extension UnitIdentifier: CustomStringConvertible {
 
     public var description: String {
-        #if canImport(Foundation) && canImport(BluetoothMetadata) && !os(WASI) && !hasFeature(Embedded)
+        #if Metadata && canImport(Foundation) && !os(WASI) && !hasFeature(Embedded)
         return self.name ?? rawValueDescription
         #else
         return rawValueDescription

Sources/Bluetooth/UnitIdentifierMetadata.swift

@@ -5,7 +5,7 @@
 //  Created by Alsey Coleman Miller on 1/12/25.
 //
 
-#if canImport(Foundation) && canImport(BluetoothMetadata) && !os(WASI) && !hasFeature(Embedded)
+#if Metadata && canImport(Foundation) && !os(WASI) && !hasFeature(Embedded)
 #if canImport(FoundationEssentials)
 import FoundationEssentials
 #else

Tests/BluetoothTests/BluetoothTests.swift

@@ -61,8 +61,12 @@ import BluetoothGATT
 
         let company: CompanyIdentifier = 76  // Apple, Inc.
 
-        #if !os(WASI)
+        // The description falls back to the raw value without the
+        // assigned-numbers metadata the Metadata trait gates.
+        #if Metadata && !os(WASI)
         #expect(company.description == "Apple, Inc.")
+        #else
+        #expect(company.description == "76")
         #endif
         #expect(company.hashValue != 0)
         #expect(company != 77)

Tests/BluetoothTests/BluetoothUUIDTests.swift

@@ -161,8 +161,14 @@ import Bluetooth
 
         #if !os(WASI)
         #expect(uuid == BluetoothUUID.Member.savantSystems2)
+        #endif
+        // The name, and the description that embeds it, come from the
+        // assigned-numbers metadata, which the Metadata trait gates.
+        #if Metadata && !os(WASI)
         #expect(uuid.metadata?.name == "Savant Systems LLC")
         #expect("\(uuid)" == "FEA9 (Savant Systems LLC)")
+        #else
+        #expect("\(uuid)" == uuidString)
         #endif
         #expect(uuid.rawValue == uuidString)
         #expect(uuid.hashValue != 0)
@@ -198,7 +204,7 @@ import Bluetooth
 
         let uuid = try #require(BluetoothUUID(rawValue: uuidString))
 
-        #if !os(WASI)
+        #if Metadata && !os(WASI)
         #expect(uuid.metadata == nil)
         #endif
         #expect(uuid.rawValue == uuidString)

Tests/BluetoothTests/GAPTests.swift

@@ -182,7 +182,13 @@ import Bluetooth
         let uuidList: GAPCompleteListOf16BitServiceClassUUIDs = [0x1803, 0x1804, 0x1802]
         let localName: GAPCompleteLocalName = "Proximity"
 
+        // The names come from the assigned-numbers metadata gated by
+        // the Metadata trait; without it the description is raw values.
+        #if Metadata
         #expect(uuidList.description == "[1803 (Link Loss), 1804 (Tx Power), 1802 (Immediate Alert)]")
+        #else
+        #expect(uuidList.description == "[1803, 1804, 1802]")
+        #endif
 
         let expectedData: [GAPData] = [flags, uuidList, localName]
         let types = expectedData.map { type(of: $0) }
@@ -219,7 +225,13 @@ import Bluetooth
         let uuidList: GAPIncompleteListOf16BitServiceClassUUIDs = [0x1803, 0x1804, 0x1802]
         let localName: GAPCompleteLocalName = "Proximity"
 
+        // The names come from the assigned-numbers metadata gated by
+        // the Metadata trait; without it the description is raw values.
+        #if Metadata
         #expect(uuidList.description == "[1803 (Link Loss), 1804 (Tx Power), 1802 (Immediate Alert)]")
+        #else
+        #expect(uuidList.description == "[1803, 1804, 1802]")
+        #endif
 
         let expectedData: [GAPData] = [flags, uuidList, localName]
         let types = expectedData.map { type(of: $0) }

Tests/BluetoothTests/GATTCharacteristicTests.swift

@@ -130,9 +130,14 @@ import Bluetooth
         (101...UInt8.max).forEach { #expect(GATTBatteryLevel(data: Data([$0])) == nil) }
 
         // test percentage
+        //
+        // `name`, `type`, and the description that falls back to `name`,
+        // come from the assigned-numbers metadata gated by the Metadata trait.
+        #if Metadata
         #expect(GATTBatteryPercentage.unitType.description == "percentage")
         #expect(GATTBatteryPercentage.unitType.name == "percentage")
         #expect(GATTBatteryPercentage.unitType.type == "org.bluetooth.unit.percentage")
+        #endif
         #expect(GATTBatteryPercentage.unitType == .percentage)
         (0...100).forEach { #expect(GATTBatteryPercentage(rawValue: $0) != nil) }
         (101...UInt8.max).forEach { #expect(GATTBatteryPercentage(rawValue: $0) == nil) }

Tests/BluetoothTests/HCITests.swift

@@ -288,7 +288,13 @@ import Foundation
         #expect(localVersionInformation.lmpVersion == 0x08)
         #expect(localVersionInformation.lmpSubversion == 0x219A)
         #expect(localVersionInformation.manufacturer.rawValue == 0x000F)
+        // The description falls back to the raw value without the
+        // assigned-numbers metadata the Metadata trait gates.
+        #if Metadata
         #expect(localVersionInformation.manufacturer.description == "Broadcom Corporation")
+        #else
+        #expect(localVersionInformation.manufacturer.description == "15")
+        #endif
     }
 
     @Test func readDeviceAddress() async throws {